Batteries store energy to provide power for an Electric Vehicle (EV) or a Plug-in Hybrid Electric Vehicle (PHEV). An electric power supply network is connected to the EV/PHEV to charge the battery. The charging system, in addition to charging the battery, may also operate other electrical systems, provide a ground path and provide for exchanging control information between the supply equipment and the charging system on the EV/PHEV.
The primary method of charging an EV/PHEV is expected to be in accordance with the SAE J1772 under AC Level 2 Charging with a charging system that is required to use a vehicle connection that requires the user to obtain a charge from a fixed charging station. The charging station may have a receptacle that accepts a SAE standard J1772 plug from the electric vehicle charging system that provides high current charging current (ie. 80 amps).
Alternatively, the vehicle may have a J1772 plug with a cord. An EV/PHEV may be charged in accordance with the developing standard SAE J1772 under AC Level One Charging by connecting to a common grounded receptacle with a cord and an electric vehicle supply equipment (EVSE) plug connector. This approach may be used if the vehicle is provided with an on-board charger that is adapted to receive single phase alternating current (AC) from the supply network with a maximum current of either 12 amps for a 15 amp circuit breaker and a NEMA 5-15 receptacle or a maximum current of 16 amps for a 20 amp circuit breaker and a NEMA 5-20R receptacle.
Carrying a cord with a J1772 plug made under the AC Level One Charging standard in the vehicle may be viewed by the vehicle user as being undesirable due to size, bulk, uncleanliness, and weight. It is anticipated that many vehicle users may forgo keeping the alternative charge cord in the vehicle for these reasons. However, there remains a concern that the vehicle user may encounter a condition where a charge is needed and no fixed power station AC power is available.
The J1772 standard includes a control pilot signal that is transmitted through the Electric Vehicle Supply Equipment (EVSE). The control pilot signal is the primary control conductor that is connected to ground through the control circuitry to perform the functions of: verifying the presence of the plug connection; permitting charging; communicating the supply equipment current rating to the EV/PHEV; monitoring the equipment ground, and the like.
The J1772 standard specifies that a fixed charging system includes a proximity sensor that prevents charging if the plug is not fully connected to the charging station or the vehicle receptacle. The vehicle charging system and fixed charging station communicate regarding the status of a mechanical latch connection to the vehicle receptacle as a condition of the vehicle charging system receiving a charge. The mechanical latch and interlock are intended to prevent arcing between the plug and receptacle.
The absence of the pilot signal or proximity sensor signal will prevent the EV/PHEV charging system from receiving a charge if it is attempted to connect the vehicle charging system to a conventional electrical extension cord.
The above problems and other problems relating to providing a charging system adaptor are addressed by the following disclosure as summarized below.